Light is a very important energy source that helps keep us warm and lets us see the world. Light travels in waves through bundles of energy called photons. The photons contain all seven colors of the rainbow. Grab a prism and check them out! Learn... more about light with this cartoon animation from StudyJams. A short, self-checking quiz is also included with this link.[more]

Current research which shows how a biological function can be turned on and off with the use of a light source, with the possibility of using it in future medications. "Food coma" takes on new meaning when nematodes are fed a light-sensitive chemical.... After the meal, the worms become paralyzed if exposed to UV light. Remarkably, the effects can be reversed under visible light. This video could also be used with a lesson on medical research, medical advancements, or the scientific process. (02:50)[more]

In this interactive activity adapted from Shedding Light on Science, learn about the primary colors of light and pigment. First, see red, green, and blue gelatin blocks used as filters to demonstrate the absorption of specific wavelengths of light. T...hen watch as three desk lamps with red, green, and blue filters show how the primary colors of light are mixed to create other colors. Finally, watch a demonstration of how paints both absorb and reflect light and how the primary colors of pigment are mixed to create other colors.[more]

Light always travels in a straight line until something gets in its way. When that happens, light can be absorbed, reflected, or refracted, depending on what kind of surface it hits. Learn more about light with this cartoon animation from StudyJams.... A short, self-checking quiz is also included with this link.[more]

In this video segment adapted from Shedding Light on Science, learn about the dispersion of light, the electromagnetic spectrum, and how sunlight contains a range of wavelengths (photons of differing energy). Isaac Newton investigated sunlight by shi...ning it through a glass prism; after the prism refracted the light, he saw a spectrum of colors. He recognized that sunlight was made up of many colors, which could not be further separated when passed through a second prism. Drops of water in the air have the same dispersion effect. In the video, a bowl of water is used to simulate a giant raindrop to show how the differing angles of refraction of different wavelengths create rainbows. Run time 03:55.[more]

In this video from the Encyclopedia of Physics Demonstrations, learn about total internal reflection. A laser beam is aligned so that the light passes through a water tank and out through an opening. As water flows out of the opening, observe how the... laser beam remains trapped in the water stream because of total internal reflection. See how the light follows the path of the water even when the flow changes. Run time 01:03.[more]

This interactive activity adapted from the National Park Service describes how humans impact the environment by creating light pollution such as light trespass, glare, and sky glow. Learn how unnecessary light wastes energy, obscures the view of the ...night sky, and affects wildlife. In addition, explore possible solutions to save energy and minimize light pollution.[more]

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